Process and apparatus for producing molten metal coated steel sheets

Abstract

A steel sheet is plated with a molten metal in a plating tank. A buffer member is provided between a sink roll submerged in the melt in the plating tank and the side wall of tank at its delivery end from which the plated steel sheet emerges. During plating, the buffer member decelerates the melt flows coming from below the sink roll so as to settle the suspended dross in the melt. The buffer member may be in the form of a rod or a plate. If desired, it may be combined with a shield plate provided below the sink roll or a raised portion formed on the bottom of the plating tank.

What is claimed is: 
     
       1. An apparatus for producing a molten metal plated steel sheet comprising: a molten metal plating tank containing a melt, said plating tank having a bottom and side walls with one side wall being located at a delivery end at which a steel sheet fed through the plating tank emerges,   a submerged sink roll disposed in the plating tank for conveying the steel sheet; and   a buffer member provided within the tank between the sink roll and the one side wall for decelerating melt flows coming from below the sink roll.   
     
     
       2. An apparatus according to claim 1 which the buffer member is a plate-shaped buffer member. 
     
     
       3. An apparatus according to claim 2 which the plate-shaped buffer member is a plate installed at an angle with respect to said one wall. 
     
     
       4. An apparatus according to claim 1 wherein the buffer member is a rod-shaped buffer member. 
     
     
       5. An apparatus according to claim 4 wherein the rod-shaped buffer member has a circular cross section. 
     
     
       6. An apparatus according to claim 4 wherein the rod-shaped buffer member has a polygonal cross section. 
     
     
       7. An apparatus according to claim 1 which further includes a current suppressing member. 
     
     
       8. An apparatus according to claim 7 wherein the current suppressing member is a shield plate disposed between the sink roll and the bottom of the tank. 
     
     
       9. An apparatus according to claim 7 wherein the current suppressing member is a raised portion projecting from a bottom of the plating tank. 
     
     
       10. Apparatus according to claim 1, including a plurality of snap rolls disposed in the plating tank above the sink roll. 
     
     
       11. Apparatus for producing a molten metal plated steel sheet, comprising: a molten metal plating tank for holding melt through which a steel sheet is to be fed, the molten metal plating tank having a delivery end at which a steel sheet fed through the plating tank emerges,   said plating tank having a side wall at the delivery end;   a sink roll positioned in the tank around which the steel sheet is to be passed;   and melt flow decelerating means positioned in the plating tank between the sink roll and said side wall for decelerating melt flows from below the sink roll to reduce adhesion of dross to the steel sheet.   
     
     
       12. Apparatus according to claim 11, wherein said melt flow decelerating means is a rod having a circular cross-section. 
     
     
       13. Apparatus according to claim 11, wherein said melt flow decelerating means is a rod having a non-circular cross-section. 
     
     
       14. Apparatus according to claim 11, wherein said melt flow decelerating means is a plate. 
     
     
       15. Apparatus according to claim 11, including current suppressing means disposed in the plating tank below the sink roll for suppressing melt flows from below the sink roll. 
     
     
       16. Apparatus according to claim 11, including a plurality of snap rolls disposed in the plating tank above the sink roll.